ShowComments handler let you to see a page containing only the comments.
It is useful if, as example, a page is really long and is long to load, too many content or too slow connection. If you want to see the comments, you don't want to wait the page to load, especially when there are many comments page (paged comments).
I'm sure of this : This handler can be improved.

Now, the code :

<?php// set default number of comments per page$d = ($_SESSION["limit_comments"])? $_SESSION["limit_comments"] : "10";